Imperial County, California, near the U.S./Mexico Border, is a low-income, primarily Latino community with a long history of cumulative exposures, including poor air quality. The county has consistently had one of the highest asthma hospitalization and emergency room visit rates in the state for school-aged children. The California Environmental Health Tracking Program- a program of the Centers for Disease Control and Prevention, the California Department of Public Health, and the Public Health Institute- is partnering with Comit Cvico Del Valle and the University of Washington to conduct a community-engaged project to reduce air pollutant exposures in this region and improve the health of its residents. The goals of the project are to: (1) Engage community members to define and map local hazards and assets to highlight factors contributing to cumulative exposures, community vulnerability and resilience; (2) Deploy a network of inexpensive real-time air monitors (Community Air Monitoring Network, or CAMN) which will relay data to the internet for immediate information on pollution levels; (3) Use state of the art land use regression modeling to develop the most accurate and detailed picture possible of PM10 and PM2.5 exposures throughout the County for identification of hot spots near vulnerable populations; (4) Develop a public health action plan for reducing exposures, improving health, and ensuring project sustainability; and (5) Conduct an evaluation of the project, including partnership processes, community involvement in the research, and resulting public health actions. This project utilizes innovative approaches with the potential to provide sustainable public health benefits and ultimately serve as a model for community-engaged environmental health action. This revision to our original grant focuses on increasing the use of the CAMN data in Imperial County, particularly in school settings, and supporting citizen science and air monitoring efforts in communities outside of the study area. This revision will (1) develop a youth environmental health leadership training institute where high school students are trained to conduct outreach and education in schools and within their communities to increase access, understanding, and use of real-time CAMN air quality data, (2) conduct a CAMN workshop with other impacted communities to increase their awareness and ability to establish a CAMN, and (3) develop a CAMN manual to provide communities with practical information, best practices, and lessons learned from our project to support the planning and development of their own CAMNs.